The invention relates to a method for setting the feed rate of a fuel pump unit, which sucks up fuel from a fuel tank, as a function of the feed pressure, which is built up by the fuel pump unit, in an outlet of the fuel pump unit, which outlet leads to an internal combustion engine, and to a fuel pump unit for this method.
In the case of a known method of this type, the fuel pump is activated as a function of operating parameters of the internal combustion engine by appropriately setting the speed of rotation of the fuel pump. In this case, the pressure which is built up by the fuel pump is limited to a defined, specified pressure by means of a pressure-limiting element. For this purpose, the speed of rotation of the fuel pump, the temperature and the suction pressure at the throttle valve of the internal combustion engine and fuel composition data are detected as operating parameters by means of sensors and are evaluated in an evaluation unit. The latter then correspondingly produces a pulsed control voltage for activating the fuel pump.
A very great and complicated outlay is required for detecting the operating parameters and for generating the activating voltage.
It is therefore the object of the invention to provide a method for setting the feed rate of a fuel pump unit, which sucks up fuel from a fuel tank, and a fuel pump unit for this method, which make it possible, in a simple manner and with little outlay, to set the fuel feed rate in accordance with the particular fuel requirement of the internal combustion engine.